STUN
Package stun implements Session Traversal Utilities for NAT (STUN) [RFC5389] protocol and client with no external dependencies and zero allocations in hot paths. Client supports automatic request retransmissions. Complies to gortc principles as core package.
See example and stun server for simple usage.
Also see gortc/turn for TURN [RFC5766] implementation and
gortcd for TURN and STUN server. This repo was merged to pion/stun
at version v1.19.0.
Example
You can get your current IP address from any STUN server by sending
binding request. See more idiomatic example at cmd/stun-client.
package main
import (
"fmt"
"gortc.io/stun"
)
func main() {
// Creating a "connection" to STUN server.
c, err := stun.Dial("udp", "stun.l.google.com:19302")
if err != nil {
panic(err)
}
// Building binding request with random transaction id.
message := stun.MustBuild(stun.TransactionID, stun.BindingRequest)
// Sending request to STUN server, waiting for response message.
if err := c.Do(message, func(res stun.Event) {
if res.Error != nil {
panic(res.Error)
}
// Decoding XOR-MAPPED-ADDRESS attribute from message.
var xorAddr stun.XORMappedAddress
if err := xorAddr.GetFrom(res.Message); err != nil {
panic(err)
}
fmt.Println("your IP is", xorAddr.IP)
}); err != nil {
panic(err)
}
}Supported RFCs
- [x] RFC 5389 — Session Traversal Utilities for NAT
- [x] RFC 5769 — Test Vectors for STUN
- [x] RFC 6062 — TURN extensions for TCP allocations
- [x] RFC 7064 — STUN URI
- [x] (TLS-over-)TCP client support
- [ ] ALTERNATE-SERVER support #48
- [ ] RFC 5780 — NAT Behavior Discovery Using STUN #49
Stability 
Package is currently stable, no backward incompatible changes are expected with exception of critical bugs or security fixes.
Additional attributes are unlikely to be implemented in scope of stun package, the only exception is constants for attribute or message types.
RFC 3489 notes
RFC 5389 obsoletes RFC 3489, so implementation was ignored by purpose, however, RFC 3489 can be easily implemented as separate package.
Requirements
Go 1.14 is currently supported and tested in CI. Should work on 1.13.
Testing
Client behavior is tested and verified in many ways:
- End-To-End with long-term credentials
- coturn: The coturn server (linux)
- Bunch of code static checkers (linters)
- Standard unit-tests with coverage reporting (linux {amd64, arm64}, windows and darwin)
- Explicit API backward compatibility check, see
apidirectory
See TeamCity project and e2e directory
for more information. Also the Wireshark .pcap files are available for e2e test in
artifacts for build.
Benchmarks
Intel(R) Core(TM) i7-8700K:
version: 1.22.2
goos: linux
goarch: amd64
pkg: github.com/gortc/stun
PASS
benchmark iter time/iter throughput bytes alloc allocs
--------- ---- --------- ---------- ----------- ------
BenchmarkMappedAddress_AddTo-12 32489450 38.30 ns/op 0 B/op 0 allocs/op
BenchmarkAlternateServer_AddTo-12 31230991 39.00 ns/op 0 B/op 0 allocs/op
BenchmarkAgent_GC-12 431390 2918.00 ns/op 0 B/op 0 allocs/op
BenchmarkAgent_Process-12 35901940 36.20 ns/op 0 B/op 0 allocs/op
BenchmarkMessage_GetNotFound-12 242004358 5.19 ns/op 0 B/op 0 allocs/op
BenchmarkMessage_Get-12 230520343 5.21 ns/op 0 B/op 0 allocs/op
BenchmarkClient_Do-12 1282231 943.00 ns/op 0 B/op 0 allocs/op
BenchmarkErrorCode_AddTo-12 16318916 75.50 ns/op 0 B/op 0 allocs/op
BenchmarkErrorCodeAttribute_AddTo-12 21584140 54.80 ns/op 0 B/op 0 allocs/op
BenchmarkErrorCodeAttribute_GetFrom-12 100000000 11.10 ns/op 0 B/op 0 allocs/op
BenchmarkFingerprint_AddTo-12 19368768 64.00 ns/op 687.81 MB/s 0 B/op 0 allocs/op
BenchmarkFingerprint_Check-12 24167007 49.10 ns/op 1057.99 MB/s 0 B/op 0 allocs/op
BenchmarkBuildOverhead/Build-12 5486252 224.00 ns/op 0 B/op 0 allocs/op
BenchmarkBuildOverhead/BuildNonPointer-12 2496544 517.00 ns/op 100 B/op 4 allocs/op
BenchmarkBuildOverhead/Raw-12 6652118 181.00 ns/op 0 B/op 0 allocs/op
BenchmarkMessage_ForEach-12 28254212 35.90 ns/op 0 B/op 0 allocs/op
BenchmarkMessageIntegrity_AddTo-12 1000000 1179.00 ns/op 16.96 MB/s 0 B/op 0 allocs/op
BenchmarkMessageIntegrity_Check-12 975954 1219.00 ns/op 26.24 MB/s 0 B/op 0 allocs/op
BenchmarkMessage_Write-12 41040598 30.40 ns/op 922.13 MB/s 0 B/op 0 allocs/op
BenchmarkMessageType_Value-12 1000000000 0.53 ns/op 0 B/op 0 allocs/op
BenchmarkMessage_WriteTo-12 94942935 11.30 ns/op 0 B/op 0 allocs/op
BenchmarkMessage_ReadFrom-12 43437718 29.30 ns/op 682.87 MB/s 0 B/op 0 allocs/op
BenchmarkMessage_ReadBytes-12 74693397 15.90 ns/op 1257.42 MB/s 0 B/op 0 allocs/op
BenchmarkIsMessage-12 1000000000 1.20 ns/op 16653.64 MB/s 0 B/op 0 allocs/op
BenchmarkMessage_NewTransactionID-12 521121 2450.00 ns/op 0 B/op 0 allocs/op
BenchmarkMessageFull-12 5389495 221.00 ns/op 0 B/op 0 allocs/op
BenchmarkMessageFullHardcore-12 12715876 94.40 ns/op 0 B/op 0 allocs/op
BenchmarkMessage_WriteHeader-12 100000000 11.60 ns/op 0 B/op 0 allocs/op
BenchmarkMessage_CloneTo-12 30199020 41.80 ns/op 1626.66 MB/s 0 B/op 0 allocs/op
BenchmarkMessage_AddTo-12 415257625 2.97 ns/op 0 B/op 0 allocs/op
BenchmarkDecode-12 49573747 23.60 ns/op 0 B/op 0 allocs/op
BenchmarkUsername_AddTo-12 56282674 22.50 ns/op 0 B/op 0 allocs/op
BenchmarkUsername_GetFrom-12 100000000 10.10 ns/op 0 B/op 0 allocs/op
BenchmarkNonce_AddTo-12 39419097 35.80 ns/op 0 B/op 0 allocs/op
BenchmarkNonce_AddTo_BadLength-12 196291666 6.04 ns/op 0 B/op 0 allocs/op
BenchmarkNonce_GetFrom-12 120857732 9.93 ns/op 0 B/op 0 allocs/op
BenchmarkUnknownAttributes/AddTo-12 28881430 37.20 ns/op 0 B/op 0 allocs/op
BenchmarkUnknownAttributes/GetFrom-12 64907534 19.80 ns/op 0 B/op 0 allocs/op
BenchmarkXOR-12 32868506 32.20 ns/op 31836.66 MB/s
BenchmarkXORSafe-12 5185776 234.00 ns/op 4378.74 MB/s
BenchmarkXORFast-12 30975679 32.50 ns/op 31525.28 MB/s
BenchmarkXORMappedAddress_AddTo-12 21518028 54.50 ns/op 0 B/op 0 allocs/op
BenchmarkXORMappedAddress_GetFrom-12 35597667 34.40 ns/op 0 B/op 0 allocs/op
ok gortc.io/stun 60.973sLicense
BSD 3-Clause License